hello moon_serenity, firefox won't run on your device because it has to little RAM memory (150 MB instead of the 384 MB that would be needed for firefox to run). in the past there have been efforts to make firefox on android run on more low-spec devices, but the 384 MB seem to be the bottom limit that has been reached of what's possible to achieve. so unfortunately i fear that there will be no way to make firefox run on the lg optimus zip.